Reversible gear pump



Jan. 12, 1954 Filed Nov. 19, 1949 J. A. LAUcK ETAL REVERSIBLE GEAR PUMP Wm /A 2 Sheets-Sheet 1 Jan. 12, 1954 .1 A. L AUcK ET A1. 2,665,636

REVERSIBLE GEAR PUMP Filed Nov. 19, 1949 2 Sheets-Sheet. 2

Patented Jan. 12, 1954 REVERSIBLE GEAR PUDIP John A. Lauck, Shaker Heights, and James A. Compton, South Euclid, Ohio, assignors to Borg-Warner Corporation, Chicago, Ill., a corporation of Illinois Application November 19, 1949, Serial No. 128,442

7 Claims. l

This invention relates to a reversible gear pump, and more particularlyto a reversible gear pump arranged to permit reversal of operation without incurring any loss of efliciency.

It is sometimes desirable to provide a gear pump in which the direction of delivery of discharge may be readily changed, or which may be driven by a motor turning in either direction Without affecting the direction of discharge. It will be readily apparent that such a pump is more adaptable than a non-reversible pump. However, heretofore most pumps in which the delivery direction may be reversed have required reversing the direction of rotation of the driving shaft and interchanging the discharge and inlet sides, the reversible feature primarily comprising designing the pump so that loss of efiieiency is held to a minimum in changing direction of delivery. At best, such pumps are a compromise arrangement and, requiring substantial symmetry of design on the inlet and the outlet sides, are, consequently, less efficient than conventional, non-reversible pumps. On the other hand, where a conventional pump is to be driven by a motor turning in the opposite direction of rotation from that for which the pump is intended, this ordinarily entails reversal of delivery direction, which result may not be desirable. Thus, such a pump is not adaptable to be driven by a motor rotating in either direction without achange in the direction` of discharge. i

An object of the present invention is to provide a fully reversible intermeshing gear type pump, which does not involve sacrifice of eiiciency in either direction of Operation, and which may be driven by a mechanism turning in either direction without affecting the direction of dis.- charge.

In accordance with one embodiment of this invention, an intermeshing gear pump may be provided wherein both pump gear shafts are provided with driving splines, both splines being positioned on the same side of the pump gears. The pump is arranged so that the mounting flange may be rotated 180 with respect to the pump body to engage either of the driving splines with a splined driving shaft extending through the flange. In this manner, the pump gears may be always driven in the same direction with Vrespect to their associated bearings` and housing, thereby, among other advantages, permitting localizing wear on the inlet side and permitting restricting the area of the high pressure zone at the discharge port, whereby journal loads and over-all wear are maintained at a low level, while at the same time permitting reversal of the delivery direction or permitting use of a driving mechanism rotating in either direction.

Other objects and advantages of the present invention will be apparent from the following detailed description taken in conjunction with the drawings wherein:

Fig. 1 is an axial, sectional view partially in elevation showing an intermeshing gear pump constructed in accordance with one embodiment of this invention;

Fig. 2 is a sectional view similar to Fig. 1, showing, however, the relative position of the parts with the mounting flange rotated from the position shown in Fig. 1 to engage the driving spline with the other of the pump gear shafts;

Fig. 3 is a transverse, sectional view taken substantially along the line 3--3 of Fig. 1;

Fig. 4 is a transverse, sectional view taken substantially along the line 4-4 of Fig. 2; and

Fig. 5 is a view similar to Fig. 3, showing, however, the relative position of the parts with the gear housing rotated 180 with respect to the mounting liange from the position shown in Fig. 1.

Referring now to the drawings, and particularly to Figs. 1 and 3 thereof, an intermeshing gear type pump is there illustrated comprising a housing 5 of generally conventional external and internal configuration and having mounted on the left end thereof a mounting fiange 6, whereby the pump may be secured to a motor or other mechanism for rotating the pump gears. A pair of intermeshing pump gears 1 and 8 are disposed `within the pump housing 5 and each has positioned on either side thereof a pair of suitable bushings 9 and I0, respectively. In the embodiment illustrated, the bushings are of the type having a tubular body and flanged gear side face engaging portions, and one set of the bushings may be made pressure loadable and axially movable in accordance with U. S. Patent No. 2,420,622 to Roth et al., where it is desired to make the pump of the pressure loadable type. The gears land -8 may have their supporting shafts I2 and I3; respectively, integrally formed therewith, as shown in Fig. 1, and the shaft portions I2 and I3 are journalled in the hollow bushings 9 and I0. The pump housing has formed therein an inlet aperture I4 and a discharge aperture I5, the aperture` I4 being positioned on the right side, as viewed in Fig, 3, and the discharge aperture I5 being positioned on the left side of the housing, wherein the pump is shown arranged for clockwise rotation of the lower pumping gear. Suitable sealing means are associated with the bushings to prevent leakage as is well known in the art.

In accordance with the present invention, each of the shaft members I2 and I3 associated with the pumping gears and 8, respectively, have xed thereto and preferably integrally i'ormed therewith, externally splined terminal portions or couplings I6 and Il, respectively. In a conventional pump, of course, only one of the pump gear shafts is provided with a splined coupling portion. The splined couplings I6 and il project to the left beyond the housing 5, thelower coupling I 'I extending into the right end of an aperture I8 formed through the lower portion of the mounting ange 6, as Viewed in Fig. 1, while the upper coupling member I is received in a cylindrical recess 20 formed in the mounting flange 6. In the arrangement of the purnpparts shown in Fig. 1, the gear 3 is the driving gear andnaccordingly, the coupling I'I is connected to a suitable source of power through a short coupling shaft 2l, the right end portion of 'which -is pro-l vided With an internally splined cylindrical recess 22 into which the splined coupling I'I extends. Rotation of the coupling 2|, by a motor Y or other driving mechanism (not shown) in a clockwise direction, as viewed in Fig. 3, causes the pumping gears to be rotated to pump uid from the inlet |13 to the outlet I5 of the pump.

It has been found in practice desirable to seal the short coupling shaft 2| to the mounting flange 5, and for this purpose an annular seal assembly 23 is positioned about the right portion of the coupling shaft, the seal assembly 23 being retained by an inwardly extending, annular flange 24 integrally formed with the left side of the mounting flange 3 at the left end of aperture I8. The seal assembly is retained at its right end by a peripheral flange 25integrally formed with the coupling shaft 2| adjacent its right end.` A helically coiled spring 25 mounted in an axially extending recess 2'! formed in the left end of the coupling I'I of gear 8 bears at its outer end against the inner side of the recess 22 formed in the coupling shaft 2|, thus urging the ange 25 against the right end of seal' assembly 23 and retaining the seal assembly tightly Vin position. A similar recess 28 is provided in the left end of coupling I6 to receive spring 26, when the gear I is to be the driving gear.

In operation, the pump housing 5 is mounted i on a motor housing (not shown) or other suitable supporting structure by the mounting ange 6. Because inthe operation of the pump, there may be some leakage past the bushings which might damage the motor, it has been found desirable to provide a drain and thus vthe left side of the mounting flange 5, as viewed in Fig. l, is provided with a large, annular recess '30 located substantially vcoaxially of the coupling shaft 2| and having connected thereto at its lower side a short passage 3| leading to a drain plug 32, threaded into the lower side of the mounting ange. `Connected to the recess 3|! at its upper side is a somewhat longer passage 33 extending upwardly to a drain plug 34. When the pump 'is used in the position shown in Fig. l, then oil or other fluid whichleaks past the bushings may be drained vby removing the plug 32,. On the other hand, when the pump is operated in the position illustrated in Fig. 2 and Fig. 4,!then the passage 33, being then at the lower side of the pump, serves `as the drain passage and by removal of the plug 34, escaped oil or other uid may be removed. It will be understood,V of course, that yeither ofV the passages vmotor .having a reverse direction of rotation from that suitable for the pump arrangement shown in Fig. l, the housing 5 is moved to the right, as viewed in Fig. 1, by removing suitable mounting bolts '(not shown) by which the housing is attached to the mounting flange 6. The

flange 6 is then lrotated 180 and the parts reassembled. In the reassembled position, the parts occupy the relative positions shown in Figs. 2 and 4.

,From Figs. 2 and 4, it will be evident that in this reverse position of the pump, the splined coupling I6 is now engaged with the shaft coupling 2|, whereas the splined coupling I'I is received in the cylindrical recess 20. From Fig. 4 it will be evident that rotation of the driving shaft, now associated with the upper pumping gear 7, in a counterclockwise direction, will cause rotation of the gear 1 in a counterclockwise direction, thereby rotating the gear 8 in a clockwise direction, in the same manner as in the arrangement of parts shown in Figs. 1 and 3. The direction of delivery andthe direction of gear rotation relatively to the associated bushings'thus remain unchanged.

If the shaftv -coupling 2| in the arrangement shown in Fig. 4 be rotated in a clockwise direction, as previously described in conjunction with Figs. 1 and 3, then it will be evident that pumping will result in a transfer of uid from the discharge passage I5 to the inlet I4. Ordinarily, this would `be of no advantage and might result in a considerable loss of eiciency where the pumps normal inlet and discharge apertures are particularly designed for maximum efiiciency in which case they will be of somewhat different size and configuration. Also, where a pump has been run for any length of time in one direction, the parts tend to wear in and a reversal of direction of rotation of the gears thereafter results in a serious loss of eiciency and greatly accelerated wear. These characteristics, of course, are true of any intermeshing gear type pump. Thus, while reversal of the direction of rotation of the pump-ing gears is possible in the arrangement illustrated, it is not generally intended.

Conversely, if the mounting ange 6 be left in the position shown in Fig. 1 and the pump housing 5 instead is revolved 180 with respect to the mounting flange Ii from the position shown in Fig. l1, then the parts will be in the position illustrated in Fig. 5 and rotation of the coupling shaft 2| in a counterclookw'ise direction, that is, the opposite direction from Athat intended with the arrangement illustrated in Fig. 3, will cause delivery of rfluid from the inlet I4 to the outlet I5, which latter outlet would then be positioned on the right side of the pump, as viewed in Figs. 3 and 4;-and thus the direction of delivery would be reversed without reversing theV direction of rotation Orf the pump gears. Y

From the foregoing, it will be evident that the novel pump arrangementinaccordance with vthis -V invention provides an Vexceptionally adaptable pump, and more particularly one in which either of the pumping gears may be the driven gear, thus permitting the direction of delivery to be reversed while permitting the gears to continue to rotate in the same direction as previously, and permitting the use of the pump with a driving mechanism turning in either a clockwise or counterclocitwise direction without affecting the direction of rotation of the pump gears.

Where herein the various parts of this invention have been referred to as being located in a right or a left position, it will be understood that this is done solely for the purpose of facilitating description and that such references relate only to the relative positions of the parts as shown in the accompanying drawings.

While but one embodiment of this invention has been shown and described, it will be understood that many changes and modifications may be made therein without departing :from the spirit or scope of the invention.

What is claimed is:

l. In a gear pump, a pump housing containing a pair of adjoining, substantially cylindrical chambers, said housing having a pair of ports formed therein on opposite sides thereof and communicating with said chambers, a pair of intermeshing pumping gears in said chambers, bearing bushing and end plate defining means associated with said pumpingA gears and supported in said housing, a shaft drivably associated with each of said pumping gears and rotatably supported in the associated bushings, a coupling termination formed on each of said shafts and extending beyond one end of said housing, said terminations being each located at the same end of the housing, a coupling and mounting plate defining means supported on said end of said housing and having a recess formed therein to receive either one of said coupling terminations and a bore to receive the other of said terminations, coupling means rotatably supported in said bore and engageable in coupling relation with the one of said coupling terminations located in said bore, and seal defining means interposed in sealing relation between said coupling means and said mounting plate bore for substantially preventing escape of fluid past said :coupling means.

2. In a, gear pump, a pump housing containing a pair of adjoining, substantially cylindrical chambers, said housing having a pair of ports formed therein on opposite sides thereof and communicating with said chambers, a pair of intermeshing pumping gears in said chambers, bearing bushing and end plate defining means associated with said pumping gears and supported in said housing, a shaft drivably associated with each of said pumping gears and rotatably supported in the associated bushings, a coupling termination formed on each of said shafts and extending beyond one end off said housing, said terminations being each located at the same end of the housing, a coupling and mounting plate defining means lsupported on said end of said housing and having a recess formed therein to receive either one of said coupling terminations and a bore to receive the other of said terminations, coupling means rotatably supported in said bore and engageable in coupling relation with the one of said coupling treminations located in said bore, seal defining means interposed in sealing relation between said coupling means and said mounting plate bore for substantially preventing escape of iiuid past said coupling means, a drain port in said pump, and means for venting fluid escaping past said seal defining means to said drain port.

3. In a gear pump, a pump housing containing a pair of adjoining chambers, said housing having apair of ports formed therein on opposite sides thereof and communicating with said chambers, a pair of intermeshing pumping gears in said chambers, a shaft drivably associated with each of said pumping gears and rotatably supported in said housing, a coupling termination formed on each of said shafts and extending beyond one end of said housing, said terminations being each located at the same end of the housing, a coupling and mounting plate defining means supported on said end of said housing and having a recess formed therein to receive either one of said coupling terminations and a bore to receive the other of said terminations, coupling means in said bore engageable in coupling relation with the one of said coupling terminations located in said bore, and seal defining means interposed in sealing relation between ,said coupling means and said mounting plate bore for substantially preventing leakage of iiuid past said coupling means.

4. In a gear pump, a pump housing having a pair of adjoining pumping chambers formed therein, said housing having a pair of ports formed therein on opposite sides thereof and communicating with said chamber, a pair of intermeshing pumping gears in said chambers for forcing fluid entering said chambers through one of said ports out of said chambers through the other `of said ports, a shaft drivably associated with each of said pumping gears and rotatably supported in said housing, a coupling termination formed on each of said shafts and extending beyond one end of said housing, said terminations being each located at the same end of the housing, a coupling and mounting plate deflning means mounted on said one end of said housing and having a recess formed therein to receive and enclose either one of said coupling terminations and a bore to receive the other of said terminations, and coupling means rotatably supported in said bore and engageable in coupling relation with the one of said coupling terminations located in said bore.

5. In a gear pump, a pump housing having a pair of adjoining pumping chambers formed therein, said housing having a pair of ports formed therein on opposite sides thereof and communicating with said chamber, a pair of intermeshing pumping gears in said chambers for forcing fluid entering said chambers through one of said ports out of said chambers through the other of said ports, a shaft drivably associated with each of said pumping gears and :rotatably supported in said housing, a coupling termination formed on each of said shafts and extending beyond one end of said housing, said terminations being each located at the same end of the housing, a coupling and mounting plate defining means mounted on said one end of said housing and having a recess formed therein to receive and enclose either one of said coupling terminations and a bore to receive the other of said terminations, and seal dening means interposed in sealing relation between said coupling means and said mounting plate bore for substantially preventing leakage of fluid through said bore.

6. In a gear pump, a pump housing having a pair of adjoining pumping chambers formed therein, said housing having a pair of ports formed therein onsopposite sides thereof and communicating with said chamber, a pair of intermeshing pumping gears in said chambers for forcing iluid entering said chambers through one of said ports out of said chambers through the other of said ports, a shaft drivably associated With each of said pumping gears and rotatably supported in said housing, a coupling termination formed on each of said shafts and extending beyond one end of said housing, said terminations being each located at the same end of ythe housing, a coupling and mounting -plate dening means mounted on said one end of said housing and having a recess formed therein to receive and enclose either one of said coupling terminations and a bore to receive the other of said terminations, seal dening means interposed in sealing relation between said coupling means and said mounting plate bore'for substantially preventing leakage of iluid past said coupling means, a drain port formed in said pump, and passage dening means for venting 11u-id escaping past said seal dening means to said drain port. Y f

7. In a gear pump, a pump housing having a pair of adjoining pumping chambers formed therein, said housing having a pair of ports formed therein on opposite sides thereof and communicating with .said chamber, a pair of intermeshing pumping gears in said chambers for forcing fluid entering said chambers through one of said portsl out of said chambers through the other of said ports, a shaft drivablyassociated with each of said pumping gears and rotatably supported in said housing, -a coupling termination formed on each of said shafts and extending beyond Vone end of said housing, said terminations beingeach located `at the same end of the housing, a coupling and mounting plate defining means mounted on said one end of said housing and having a'recess formed therein to receive and enclose either one of said coupling terminations and a bore to receive the other of said terminations, a drain port formed in said pump, a recessed drain area encircling said bore and spaced therefrom, and passage Ydefining means communicating said drain area to said drain port.

JOHN A. LAUCK.

JAMES A. COMPTON.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 883,931 Callan Apr. 7, 1908 1,132,747 Sundh Mar. 23, 1915 1,418,741 Stallman June 6, 1922 1,642,454 Malmstrom Sept. 13, 1927 1,765,724 Heil June 24, 1930 Y 1,902,347 Vogt et a1. Mar. 21, 1933 1,913,633 Heil et al June 13, 1933 2,096,490 Hansen Oct. 19, 1937 2,105,428 Maglott Jan. 11, 1938 2,193,273 Dietzel Mar. 12, 1940 2,247,454 Thomson July 1, 1941 2,316,555 Collier Apr. 13, 1943 2,467,524 Fernstrum Apr. 19, 1949 OTHER REFERENCES Ser. No. 227,468, Egersdorfer (A. P. C.), published May 25, 1943.

Ser. No. 321,834, Heimbach (A. P. C.), published May 25, 1943. 

